Yarn sizing



United States Patent YARN SIZING Richard C. Hanson, Hopkins, Minn., assignor to Ashland Oil & Refining Company, Ashland, Ky., a corporation of Kentucky No Drawing. Filed Apr. 4, 1967, Ser. No. 628,255

Int. Cl. D0611 15/00 US. Cl. 117-621 5 Claims ABSTRACT OF THE DISCLOSURE A process for sizing textile yarn comprising, in sequence, the steps of:

(A) applying to the yarn a polyester dispersion comprising:

(1) water and (2) a nonoxidizing, water dispersible polyester comprising the reaction product of a polycarboxylic acid and a polyhydric alcohol, and then:

(B) removing the water.

Yarns, sized in accordance with the present invention, can be woven into textile fabrics. The polyester sizing can then be removed from the fabric or can be permanently incorporated therein by the use of cross-linking agents. Fabrics of yarns sized in accordance with the present invention exhibit a greater receptivity to dye and other textile treating agents than textiles of yarns treated with other sizes.

In the textile industry, yarns are frequently sized before incorporating them into woven or nonwoven fabrics. The sizing process consists of depositing an amount of size onto the yarn sufificient to effect the desired results. Yarns are sized in order to increase their tensile strength and, in certain cases, to reduce the yarn-to-metal coeflicient of friction. A stronger yarn is desirable in order to minimize breakage in subsequent textile operations such as weaving. A low strength results in breakage which causes interruption of the weaving operation and increases costs. A low yarn-to-metal coeificient of friction is desirable in order to minimize yarn and machine wear.

Many types of sizes have been used in the past. In particular, starch, starch derivatives, and animal glue have been used in the case of cotton yarns, whereas polyvinyl alcohol has found wide acceptance as a size for yarns of synthetic materials such as polyamides (nylon); acrylic fibers such as polyacrylonitrile; and polyesters such as polyethylene terephthalate.

Although these prior art sizes perform quite well, they interfere with subsequent finishing steps and must be removed before these finishing steps can be performed. Examples of these subsequent finishing steps include, among others, bleaching, dyeing softening, and the application of self-smoothing, wash and wear, or permanent press finishes.

Under certain conditions, it is desired to leave the size on the fabric. These fabrics are termed loom finished goods and have found wide consumer acceptance in the trade for special applications. Immediately after removal from the loom and prior to any washing operation, these loom finished goods have a hand which is affected by the characteristics of the fabric, the yarn and, in particular, the type and amount of size. However, in subsequent washings the size is removed, creating an undesirable change in the hand of the fabric. Since the abovedescribed sizes are all water soluble or water dispersible,

it has heretofore been impossible to provide loom finished goods containing a permanent size.

It is therefore an object of the present invention to provide a novel process for sizing textile yarns.

Another object of the present invention is to provide a novel process for sizing textile yarns which precludes the necessity of removing the size prior to subsequent finishing steps.

A further object of the present invention is to provide a novel process for sizing textile yarns which provides a sized fabric in which the size can be optionally removed or optionally retained on the fabric.

A still further object of the present invention is to provide a process for sizing textile yarns comprising the further step of permanently incorporating the yarn size into the textile thereby creating permanently sized loom finished goods.

Yet another object of the present invention is to provide a novel process for sizing textile whereby the strength and softness of the sized fiber is increased.

Still another object of the present invention is to provide a novel process for sizing textile yarns which produces a sized fabric which does not interfere with subsequent steps such as bleaching, dyeing, softening, or the application of self-smoothing, wash and wear, or permanent press finishes.

Additional objects and advantages of the present invention will be apparent by reference to the following detailed description thereof.

The above and other objects are accomplished by providing a process for sizing textile yarns comprising, in sequence, the steps of:

(A) applying to the yarn a polyester dispersion comprising:

(1) water and (2) a nonoxidizing, water dispersible polyester, and

then:

(B) removing the water.

The polyesters useful in the present invention are, in general, the reaction product of a polycarboxylic acid and a polyhydric alcohol which, in a preferred embodiment, contains, in addition, an amount of a suitable oil or a fatty acid. In a second preferred embodiment of the present invention, the polyester contains an amount of a polyhydric alcohol which is a polyalkylene glycol. Certain of the polyesters useful in the present invention have found utility in the textile industry as hand modifiers. In this utility, they have been applied primarily to the woven fabrics rather than to the yarn from which the woven fabrics are manufactured.

The polycarboxylic acids which can be employed to produce the polyesters useful in the present invention include the aliphatic polycarboxylic acids of 4 to 18 carbon atoms and the aryl polycarboxylic acids. Examples of the aliphatic polycarboxylic acids include, among others, adipic acid, succinic acid, glutaric acid, sebacic acid, azelaic acid, and their extant anhydrides. Examples of suitable aromatic polycarboxylic acids include, among others, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid, as well as their extant anhydrides.

The polyhydric alcohols which can b reacted with the polycarhoxylic acids in order to give polyesters useful in the present invention are preferably those of 2 to 8 carbon atoms, and most preferably the diols, examples of which include, among others, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,2- or 1,3-dipropylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,3-pentanediol, and 1,5-pentanediol. Higher polyhydric alcohols such as trimethylol propane and 3 pentaerythritol can be used in minor amounts which do not materially alter the linear nature of the polyester. Examples of suitable oils include, among others, linseed oil, tung oil, castor oil, dehydrated castor oil, safllower oil, soya oil, tall oil, cottonseed oil, olive oil, and cocoanut oil, and their fatty acid derivatives. The fatty acid derivatives of the above-described oils contain varying amounts of fatty acids such as myristic acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, linoleic acid, caprylic acid, capric acid, lauric acid, linolenic acid, eleostearic acid, and ricinoleic acid. These oils and fatty acids must be used in the form of their hydrogenated derivatives in order to be nonoxidizing.

In a preferred embodiment of the present invention, a portion of the polyhydric alcohol is a polyalkylene glycol having an average molecular weight in the range of 600 to 6,000, preferably in the range of 1,000 to 2,000. Suitable polyalkylene glycols include, among others, polyethylene glycol, polypropylene glycol, and mixtures thereof. These polyalkylene glycols are produced in a manner well-known in the art by the condensation of alkylene oxides such as ethylene oxide or propylene oxide to produce a glycol having multiple ether linkages and having the desired molecular weight. Commercially available polyalkylene glycols of the type suitable for incorporation into the polyesters useful in the present invention are sold under the tradenames Carbowax, Polyglycol E, and Polyglycol P. If desired, mixtures of the above polyalkylene glycols can be employed. The polyalkylene glycol can comprise from to 100%, and preferably from 20 to 70% of the polyhydric alcohol.

The polyesters useful in the present invention can be produced by combining the desired quantities of the indicated reactants at esterification temperatures, generally in the range of 200 to 600 F. As is well-known in the art, the reactants are generally combined in stoichiometrically equivalent amounts, or, in certain applications, with a slight excess of the polyhydric alcohol. Detailed procedures for the synthesis of certain polyesters useful in the present invention are described in US. Patent 3,223,659. Other polyesters useful in the present invention can be produced by similar procedures or by other procedures well-known in the polyester art.

The polyesters useful in the present invention are nonoxidizing, which means that they do not cure or crosslink by the absorption of atmospheric oxygen, with resultant polymerization. The polyesters useful in the present invention can be cured by other means, described more completely below. The nonoxidizing character of the polyesters is ensured by employing only nonoxidizable reactants such as saturated fatty acids or oils. Naturally occurring oils and unsaturated fatty acids can be rendered nonoxidizable by hydrogenation by procedures Well-known in the art. The preferred saturated fatty acids are saturated monocarboxylic acids of 6 to 18 carbon atoms, examples of which include, among others, caproic acid, caprylic acid, lauric acid, myristic acid, stearic acid, and 4-ethyl-pentadecanoic acid.

The polyesters useful in the present invention are rendered water dispersible by stopping the esterification reaction at the desired acid number and then neutralizing the resultant polyester with an amount of a base. The desired acid number is dependent upon the presence or absence and the quantity of the polyalkylene glycol employed. In polyalkylene glycol-free polyesters, it is desired that the polyester have an acid number of 30 to 100 prior to neutralization, whereas when the polyesters contain the preferred amounts of polyalkylene glycol, they can have an acid number of 2 to 30 prior to neutralization. These lower acid number polyalkylene glycol-containing polyesters are the preferred polyesters for use in the present invention. The acid number is the number of milligrams of potassium hydroxide necessary to neutralize the nonvolatile content of one gram of the polyester.

The bases which can be employed to neutralize the polyesters useful in the present invention include the inorganic bases or, preferably, the organic bases, the most preferable class of which is the tri(lower alkyl) amines. Examples of suitable inorganic bases include potassium hydroxide, sodium hydroxide, and ammonia. Examples of the preferred tri(lower alkyl) amines are those containing 3 to 24 carbon atoms, such as triethylamine, trimethylamine, ethyldimethylamine, triethanolamine, and morpholine. 'Suflicient amine is used to neutralize the acidity present in the polyester as indicated by the acid number, and, in general, to give the polyester a pH of greater than 7 and preferably 7 to 9.

The polyesters useful in the present invention can be applied to the yarn by any convenient means; however, it is preferred to immerse the yarn in a dispersion of the polyesters and a solvent, preferably water, at temperatures of 50 to 212 F. The dispersion can contain from 2 to 40% by weight of the polyester and correspondingly from 98% to 60% by weight of water. Other noninterfering substituents such as soaps, lubricants, and the like can also be present in the polyester dispersion. The textile yarn can be passed through the polyester dispersion at any convenient linear rate of speed. The rate of speed and the concentration of the polyester in the polyester dispersion is controlled such that the dried, sized yarn contains from 1 to 20% of the polyester by weight based on the combined weight of the polyester and the yarn.

The polyester solvent, usually water, can be removed by any convenient means such as drying in air at ambient conditions (68 F., 50% relative humidity) or by force drying at elevated temperatures of 70 to 200 F.

When it is desired that the polyester remain permanently in the fabric, the polyester can be cross-linked by contacting it with a cross-linking-resin. The polyester can be cross-linked at any stage in the production after the polyester has been applied to the yarn. However, it is most desirable to cross-link the polyester after the polyester-containing yarn has been formed into the fabric. Cross-linking is effected by contacting the polyester-containing yarn or fabric with a cross-linking resin such as aminoplasts, phenol formaldehyde resins, urea formaldehyde resins or methylolated urea formaldehyde resins, melamine formaldehyde resins, and the like. Suitable cross-linking resins are well-known in the polyester art and their synthesis and selection is well within the skill of those routinely engaged in this art. Cross-linking is generally effected by immersing the fabric in a solution containing from 2 to by weight of the cross-linking resin, removing the fabric, squeezing excess solution from the fabric, and heating the fabric at cross-linking temperatures of from about 200 to 450 F., and preferably from 225 to 300 F.

When it is desired to permanently incorporate the polyester into the fabric by reaction with a cross-linking resin or by reaction with a reactive finishing agent, polyester is chosen which has a hydroxyl value of 30 to 350, and preferably from 45 to 250. Hydroxyl value, a term wellknown in the polyester art, is the number of milligrams of potassium hydroxide necessary to neutralize the acetic acid liberated by the hydrolysis of the reaction product of acetic acid and one gram of the nonvolatile content of the polyester.

The invention may be better understood by reference tothe following examples in which all parts and percentages are by weight unless otherwise indicated. These examples are illustrative of certain embodiments designed to teach those skilled in the art how to practice the invention and to represent the best mode contemplated for carrying out the invention, and are not intended to limit the scope thereof in any manner.

EXAMPLE 1 This example illustrates the synthesis of a water dispers1ble polyester useful in the present invention.

The vindicated quantities of the following ingredients,

are charged to a reactor fitted with a mechanical stirrer, thermometer, water separator and reflux condenser:

Ingredient: Grams Hydrogenated cocoanut fatty acids 530.0 Phthalic anhydride 686.0

Polyethylene glycol (average mol wt. 1450)-- 280.0 Triphenyl phosphite 3.2 Carbitol acetate 40.0

The reactor and its contents are heated together to a temperature of 500 F. and held for a period of one hour under an atmosphere of nitrogen.

The reaction mixture is thereafter cooled to 300 F. and trimethylol ethane (579 grams) added. The temperature of the reaction mixture is raised to 510 F. and main- .tained at that temperature under agitation for seven and one-half hours, at which time the acid value is 8.65.

The product, on cooling, is a clear, nonoxidizing resin having a Gardner viscosity of K at 60% nonvolatile in ethylene glycol mono butyl ether. The color is 7 on the Gardner scale.

The foregoing resin is thinned with water by the following procedure. The resin (815.5 grams) prepared as described above and at 100% nonvolatile is admixed with triethylamine (12.75 grams) at a temperature of 165 F. in a system fitted for reflux. Water (1211.75 grams) is added over a period of 20 to 40 minutes. The heat is applied during the first half of the water addition, the mixture being well agitated during this addition. This mixture is cooled to room temperature, and is termed Polyester Dispersion A.

EXAMPLE 2 This example illustrates the synthesis of another water dispersible polyester useful in the present invention.

The indicated quantities of the following ingredients are charged to a reactor fitted with a mechanical stirrer, thermometer, water separator, and reflux condenser.

Ingredient: Grams Para tertiary butylbenzoic acid 401.0 Phthalic anhydride 148.0 Adipic acid 292.0

Polyethylene glycol (average mol wt. 1450) 165.0 Triphenyl phosphite 1.6 Carbitol acetate 20.0

The reactor and its contents are heated to a temperature of 500 F. and held for a period of one hour under an atmosphere of nitrogen. The reaction mixture is thereafter cooled to 300 F. and trimethylol ethane (416 grams) added. The temperature of the reaction mixture is raised to 500 F. and maintained under agitation at that temperature for eight hours.

The product, on cooling, is a clear, viscous, nonoxidizing resin having an acid value of 6.5. The resin at 60% nonvolatile in ethylene glycol mono butyl ether has a Gardner viscosity of to P and a Gardner color of 7.

A clear water solution is prepared from the foregoing resin by the following procedure. 345 parts by weight of the resin prepared as described above and at 100% nonvolatile are admixed with 4 parts by weight of triethylamine at a temperature of about 165 F. in a system fitted for reflux. 514 parts by weight of water are added over a period of 20 to 40 minutes. The heat is applied during the first half of the water addition, the mixture being well agitated during this addition. The resulting product is a clear solution which has a nonvolatile content of 40%, a pH of 8.2, and a viscosity of 460 cps. This product is termed Polyester Dispersion B.

EXAMPLE 3 This example illustrates the synthesis of an oil-free polyester useful as a textile size according to the present invention.

Glycerin (43.4 grams), trimethylol ethane (117.0 grams), pentaerythritol (138.6 grams), phthalic anhydride (420 grams), and xylene (14.5 grams) are charged to a flask fitted with a mechanical stirrer, a nitrogen inlet tube, a thermometer, and a water trap with a reflux condenser. The flask and its contents are heated to 360 F., at which point water begins to distill from the reaction mixture. The reaction is continued at a temperature of from 375 to 380 F. until the acid value reaches 124. The resin is cooled to 212 F.

A 28% aqueous solution of ammonia (107 grams) and water (343 grams) is added to 800 grams of the rapidly agitated resin solution. The clear aqueous resinous solution is cooled to room temperature. Upon cooling, the solution exhibits a viscosity of 1330 cps. (measured using a #4 spindle at rpm. on a Brookfield RVT Ciscometer), a pH of 8.9, and a nonvolatile content of 61.0%. This material is termed Polyester Dispersion C.

EXAMPLE 4 This example illustrates the synthesis of yet another water dispersible polyester resin which can be employed as a yarn size according to the present invention. This polyester contains a polyalkylene glycol.

The indicated quantities of the following ingredients are charged to a three-neck flask fitted with a thermometer, a stirrer, a reflux condenser, and a Dean-Stark water separation trap.

Ingredient: Grams Isophthalic acid 200.0 Adipic acid 46.2

Carbowax 1540 (polyethylene glycol; average molecular weight of 145 0) 99.0 Hydrogenated bisphenol-A 75.0

Trimethylol ethane 190.0

A small amount (7%) of high boiling solvent (Carbitol acetate) is added to the flask which is then heated to 482 F. and held at this temperature for three hours. After this time, the acid value has fallen to 10.8. The flask is cooled to 284 to 302 F. An aqueous amine solution is prepared in another flask by mixing water (592 grams) and triethylamine (8 grams). This aqueous amine solution is heated to F. Then 500 grams of the hot polyester resin are added to the aqueous amine solution under rapid agitation to form a dispersion. Upon cooling, the resulting polyester dispersion has an opalescent appearance. The viscosity is 1630 cps. (measured using a #4 spindle at 100 r.p.m. on a Brookfield RVT Viscometer). The pH is 7.3. This polyester dispersion is termed Polyester Dispersion D.

EXAMPLE 5 The example illustrates the synthesis of another polyalkylene glycol-containing polyester useful in the present invention.

The indicated quantities of the following ingredients are charged to a three-neck flask fitted with a thermometer, a stirrer, a reflux condenser, and a Dean-Stark water separation trap.

Ingredient: Grams Isophthalic acid 498.0 Neopentyl glycol 324.0 Adipic acid 438.0 Carbowax 1540 (polyethylene glycol; average molecular weight of 1450) 360.0 Trimethylol ethane 444.0

The flask and its contents are heated for 8 hours at 383 F., at which time the acid value of the mixture is 22.9. An aqueous amine solution is prepared in another flask by mixing water (592 grams) and triethylamine (8 grams). This aqueous amine solution is heated to 140 F. Then 500 grams of the hot polyester resin are added to the aqueous amine solution under rapid agitation to form a dispersion. Water is added until the resultant dispersion has a nonvolatile content of 43%. The viscosity is 7850 cps. (measured using a #4 spindle at 20 r.p.m. on a Brookfield RVT 7 viscometer). The pH is 7.0. This material is termed Polyester Dispersion E.

EXAMPLE 6 This example illustrates the sizing of yarn according to the present invention.

A single strand of cotton yarn is sized by passing it through Polyester Dispersion A at a temperature of 68 F. The yarn so treated is then dried at 200 F. The dried yarn contains 4% by Weight of the polyester from Polyester Dispersion A. This yarn has excellent strength and exhibits a low yarn-to-metal coefficient of friction. Cotton fabric woven of this yarn exhibits an excellent hand.

EXAMPLE 7 This example illustrates the sizing of yarn according to the present invention.

The procedure of Example 6 is repeated with the single exception that Polyester Dispersion A is replaced in each of four successive runs by an equal Weight of polyester Dispersions B, C, D, and then E. The woven fabric exhibits an equally advantageous hand.

EXAMPLE. 8

This example illustrates the desizing of a textile fabric according to the present invention.

The fabrics sized in accordance with Example 7 are agitated in water at 180 F. for twenty minutes, removed, rinsed once in a separate bath water at 150 F. and dried in air at 68 F. for 2 hours. The resultant fabrics are free of polyester.

EXAMPLE 9 This example illustrates the permanent size feature of the present inventionwherein the polyester remaining on the yarns of the fabric is cross-linked with a melamine formaldehyde cross-linking agent.

A cross-linking solution is prepared by mixing a melamine formaldehyde condensate commercially available as Monsanto RI-2027 (70 grams) and Water (30 grams). The fabric of Example 7 (50 grams) containing the polyester of Polyester Dispersion D is immersed in this solution, removed, squeezed to remove excess solution, and allowed to dry at room temperature (68 F.) for 15 minutes to remove the water. The fabric is then placed in an oven at 248 F. for 30 minutes to cure the polyester. The resultant fabric has a slightly stiffer hand. Three successive washings in water at 180 F. fails to remove the polyester as indicated by only a slight reduction in the Weight of the fabric.

EXAMPLE 10 This example illustrates the permanent size feature of the present invention wherein the polyester remaining on the yarns of the fabric is cros-linked with a melamine formaldehyde cross-linking agent.

A cross-linking solution is prepared by mixing a melamine formaldehyde condensate commercially available as Monsanto RI-2027 (70 grams) and Water (30 grams). The fabric of Example 7 (50 grams) containing the polyester of Polyester Dispersion E is immersed in this solution, removed, squeezed to remove excess solution, and allowed to dry at room temperature (68 F.) for minutes to remove the water. The fabric is then placed in an oven at 248 F. for 30' minutes to cure the polyester. The resultant fabric has a slightly stiff hand, but is softer than the resultant fabric of Example 9. Three successive washings in water at 180 F. fails to remove the polyester as indicated by only a slight reduction in the weight of the fabric.

EXAMPLE 11 This example illustrates the advantages of fabrics sized in accordance with the present invention and in particular the receptivity of a wash and Wear finish.

The fabric of Example 7 containing the polyester of Polyester Dispersion B is placed in a solution of Water (1000 grams) and the wash and wear finishing agent grams) of the following formula:

The fabric is then heated for 20 minutes at 212 F. The treated fabric exhibits characteristic wash and wear properties. A comparable fabric sized with polyvinyl alcohol does not exhibit these properties.

What is claimed is:

1. A process for sizing textile yarn comprising in sequence, the steps of:

(A) applying to the yarn a polyester dispersion consisting essentially of (1) from 98 to 60% by weight water and correspondingly (2) from 2 to 40% by weight of a nonoxidizing,

water dispersible polyester comprising the reaction product of a polycarboxylic acid and a polyhydric alcohol and then:

(B) drying the yarn to remove the Water.

2. The process of claim 1 wherein the polyester is the neutralized reaction product of:

(A) a polycarboxylic acid,

(B) a polyhydric alcohol of 2 to 8 carbon atoms, and

(C) a saturated monocarboxylic acid of 6 to 18 carbon atoms.

3. The process of claim 1 wherein the polyester is the neutralized reaction product of:

(A) a polycarboxylic acid,

(B) a polyhydric alcohol of 2 to 8 carbon atoms, and

(C) a polyalkylene glycol having a molecular Weight of 600 to 6 ,000.

4. The process of claim 3 wherein the neutralizing agent is a tertiary amine containing from 3 to 24 carbon atoms.

5. A process for sizing yarn-containing fabrics comprising, in sequence, the steps of:

(A) applying to the yarn a polyester dispersion consisting essentially of (1) from 98 to 60% by weight water and correspondingly (2) from 2 to 40% by weight of a nonoxidizing,

Water dispersible polyester comprising the reaction product of a polycarboxylic acid and a polyhydric alcohol and then:

(B) drying the yarn to remove the water, and then (C) weaving the yarn into a fabric, and then (D) applying to the fabric a cross-linking agent for the polyester, and then (B) heating the fabric at a temperature of from 200-450 F. to effect cross-linking.

References Cited UNITED STATES PATENTS 2,915,486 12/1959 Shelley 260-22 X 2,957,837 10/1960 Smith et al. 260-22 3,077,459 2/1963 Hershey et a1 260-22 3,223,658 12/1965 Kraft et a1. 260-22 3,223,659 12/1965 Curtice et al 260-22 3,321,819 5/1967 Walter et al 117-1395 X FOREIGN PATENTS 790,477 2/ 1958 Great Britain.

MURRAY KATZ, Primary Examiner M. R. LUSIGNAN, Assistant Examiner US. Cl. X.R. 

